The studied interval from 647.72 to 955.32 mbsf in Hole 986D contains the following stratigraphic units based on foraminifers: the planktonic Neogloboquadrina atlantica (sinistral) Zone, the benthic Melonis zaandamae-Cassidulina teretis Zone, and four agglutinated assemblages designated as AFA1 through AFA4. The lowermost 55 m of the interval are barren of planktonic and calcareous benthic foraminifers but contain varying amounts of agglutinated taxa (Fig. 6).
Paleomagnetic data show that the bottom of the hole is in the Matuyama Chron, which implies an age of <2.6 Ma (Channell et al., Chap. 10, this volume). The occurrence of N. atlantica (sin.) implies an age not younger than 2.4 Ma for the top of the interval. The paleomagnetic data indicate a maximum age of ~1.7 Ma for the top of the interval (Channell et al., Chap. 10, this volume) and show a discrepancy between the paleomagnetic and the biostratigraphic data in this part of the hole.
A strongly variable abundance of planktonic and calcareous benthic foraminifers indicates alternating glacial and interglacial conditions. The planktonic fauna suggests a generally cold ocean with short warm to transitional surface-water ingressions and is consistent with the changing content of calcareous benthic Arctic and boreal species. Most of the planktonic specimens are well preserved and show no sign of having been reworked. Many of the calcareous benthic specimens, however, are broken, indicating considerable reworking.
The planktonic and calcareous benthic assemblages are correlated with similar faunas in Hole 910C on the Yermak Plateau, Hole 643A on the Vøring Plateau, the exploration Well 7117/9-1 on the Senja Ridge, and the exploration Well 7316/5-1 in the Vestbakken Volcanic Province.
The agglutinated assemblages represent alternating porous noncompressed bathyal in situ faunas and silicified compressed redeposited taxa as well as mixed faunas of in situ and redeposited specimens (see Fig. 7). The exclusively agglutinated assemblages occurring in three segments of Hole 966D indicate that the deposition has taken place below the local carbonate compensation depth.